Briefly

Pyramid operations

Pyramid operations


Watch this series:
1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321

111111111 x 111111111 =?

Without performing any calculation, Would you be able to guess the result of the last term of the series?

Solution

With each digit added to the multiplying we get one more figure in the result always following the increasing-decreasing pattern.

1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321